NAME

       nbdkit_stdio_safe - is it safe to interact with stdin and stdout

SYNOPSIS

        #include <nbdkit-plugin.h>

        int nbdkit_stdio_safe (void);

DESCRIPTION

       The "nbdkit_stdio_safe" utility function returns whether or not it is safe to interact with stdin and
       stdout during the configuration phase.

       This is needed because when the nbdkit -s option is used the plugin must not directly interact with
       stdin, because that would interfere with network communication.

       The result of this function only matters in callbacks up to ".config_complete".  Once nbdkit reaches
       ".get_ready", the plugin should assume that nbdkit may have closed the original stdin and stdout in order
       to become a daemon.

       nbdkit-sh-plugin(3) uses this function to determine whether it is safe to support "script=-" to read a
       script from stdin.  Also constructs like "password=-" (see nbdkit_read_password(3)) are disabled when
       reading from stdio is not safe.

RETURN VALUE

       The function returns 1 (safe) or 0 (not safe).

       It cannot return an error.

LANGUAGE BINDINGS

       In nbdkit-ocaml-plugin(3):

        NBDKit.stdio_safe : unit -> bool

       In nbdkit-python-plugin(3):

        import nbdkit
        is_safe = nbdkit.stdio_safe()

       In nbdkit-rust-plugin(3):

        use nbdkit::*;
        pub fn is_stdio_safe() -> bool

HISTORY

       "nbdkit_stdio_safe" was added in nbdkit 1.20.

SEE ALSO

       nbdkit(1), nbdkit_read_password(3), nbdkit-plugin(3), nbdkit-filter(3).

AUTHORS

       Eric Blake

COPYRIGHT

       Copyright Red Hat

LICENSE

       Redistribution and use in source and binary forms, with or without modification, are permitted provided
       that the following conditions are met:

       •   Redistributions  of  source  code must retain the above copyright notice, this list of conditions and
           the following disclaimer.

       •   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
           the following disclaimer in the documentation and/or other materials provided with the distribution.

       •   Neither the name of Red Hat nor the names of its contributors may  be  used  to  endorse  or  promote
           products derived from this software without specific prior written permission.

       THIS  SOFTWARE  IS  PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
       INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND  FITNESS  FOR  A  PARTICULAR
       PURPOSE  ARE  DISCLAIMED.  IN  NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
       INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,  PROCUREMENT  OF
       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
       ON  ANY  THEORY  OF  LIABILITY,  WHETHER  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
       DAMAGE.

nbdkit-1.40.4                                      2024-09-29                               nbdkit_stdio_safe(3)